Fuel-supply system



APTIV3H'1929- l `T. A. PEEBLES y 1,710,839

FUEL SUPPLY SYSTEM Filed sept. s, 1925 Patented Apr. 3o, 1929.

UNITED STATES PATENT orifice.

THOMAS A. PEEBLES, OF PITTSBURGH, PENNSYLVANIA.

FUEL-SUPPLY SYSTEI.

Application llled September l the rate of flow of either ofthe fluidswill vary and the proportions of air and fuel be .P

changed by any variations in the resistance to the flow of eitherfluidbetween the controllin valve and the burners. The air l5 which 1susually assed through a preheating device such, olf-1A example, as acheckerwork is particularly sub]ect to this drawback, due to the fact`that such a preheating device becomes cloo'ged with dirt and foreign 2Qmatter resulting fiom various causes.

An ob'ect of this invention is to provide a system or supplyino' fuel tofurnaces of such construction andD arrangement that any variations inthe resistance to the flow of fluid from the controlling valve to theburners will be so compensated for as to maintain theproper proportionsand rate of flow of the iuids forming the fuel. l

A further object is to provide a system for supplying fuel vto furnaceshaving a means for maintaining a constant quantity llow of the fluidsfor any given setting of the valves, regardless of variations in theresistance to flow resulting from such a device as a checkerwork usedfor preheating air.

A still further object is to provide a system of the type set forthwhich will be simple to manufacture, easy to control and reliable andaccurate in operation.

4o These, and other objects which will be apparent to those skilled inthis particular art, are accomplished by means of this invention, oneembodiment of which is illustrated in the accompanying drawing, which isa diagrammatic vlew of a fuel supply system constructed in accordancewith one form of this invention., v

In the particular embodiment of this invention illustrated in thedrawing, the system is arranged so as to automatically comensate forvariations in the resistance to the flow of air from the controlling airvalve to the burners in such a way as to supply the burners with aconstant quantity of air despite any change in such resistance. Ob-

s, 192s. semi 1ro. 5434s.

viously, the same stem can be so arranged as to compensate or anyvariations in the resistance to the iiow of the fluid fuel such forexample, as oil -or gas, but in view of the fact that the latter flowsdirectly from the valve to the burners and `that the .air passesvthrough such devices as a fan and a preheating c eckerwork or the like,the latter will be subject to a varying resistance and the presentdescription is, therefore, ap-

lied to a construction in which variations 1n esistance to the flow ofair are compensated or. t

The diagrammatic illustration in the drawmgdlscloses a supply conduit 1,having any des1red form of valve, such, for example, as the butterflyvalve 2, for varying the rate of liow of fluid fuel such as oil or gasfrom a source'of constant pressure (not shown) to the furnace burners(not shown).

, An air supply conduit 3 is similarly provided with a valve such as thebutterfly valve 4' for controlling the rate of flow of air through theconduit from a source at atmospheric pressure and the two valves-2 and 4may have their operating arms 5 and 6, respectively, connected by aconnecting bar 7 or the like for unitary movement by any form ofoperating means such as the hand lever 8.

A fan 9, operated, for example, by a motor or turbine 10 draws the airthrough the connecting conduit 3 and passes it through a second conduit11 to the preheating checkerwork 12 which may be of any well knownconstruction. From the latter, the air is passed to the furnace burnerswhere it is mixed with-the gas supplied through the conduit, and thevalves 2 and 4 are so correlated that the fluids are delivered in suchproportions 'as to form the most eicient combustible mixture. Opening orclosing of the controlling valves 2 and 4 will cause a proportionatevariation in the quantity flow of the fluids passing through theconduits to, the burners. v Y

After the furnace has been in use for some time,` the passages 'of thecheckerwork V through which the air flows become clogged with dirt andother foreign matter, with the result that fo: a given amount of openingof the air controlling valve 4 a smaller quantity of air will pass, dueto the increased resistance to such passage in the checkerwork. As a,direct result of this reduced flow of air, 11o

the most eliicient proportion of air to gas which is ultimately suppliedto the burners is destroyed resulting in faulty,inefiicient operation.

I have found that this dilliculty 'can be remedied, and a constantquantity of air caused to ilowfor any given opening of the aircontrollin valve 4, by maintainin the pressure in t e air conduit 3beyon the valve 4 constant, so that aconstant pressure drop ismaintained across the air controlling valve. n

The preferred mechanism foraccomplishing this .result is illustrated inthe drawing and consists of a second-valve 13, the operating 1ever,14 ofwhich is connected-by a rod to a pressure, responsive valve regulator`16 such, for example, as the regulator, disclosed' in Patent No.1,150,097, granted August 17, 1915, to Francis H. Brown. The

f regulator is conn#n ated to the air conduit `be tween the two valves 4and 13 by a pressure tap 17 andis adjusted. so as to open and close 4the valve 13 .and maintain a constant sub will tend to increase.

atmospheric pressure' in the air conduit bc` yond the controlling valve4. ,It will thus be seen that in View of the fact that the air issupplied tothe conduit from a source' at atmospheric pressure, therewill be maintained a constant pressure drop across the air controllingvalve with the result that any variation in the opening'of the valve 4will cause a pro ortionate variation in the quantity flow o air pastthevalve, through the' conduit and to the burners. For example,

as the checkerwork 12 clogs up so as to in erease'the resistance totheair flow, the pressure in the air conduit 3 beyond the valve 4; Such anincrease,

Yconduit-1 to the burners. A

however, will actuate the pressure responsive regulator 16 so as to openthe valve 13 an amount just sufficient to com nsate for the increasedresistance of the clleeckerwork 12. The result is the maintainingof aconstant total resistance to air flow from the controlling valve 4 tothe burners so that any given position of the valves 2 and 4 will pass aconstant uantity of air and gas to the burners in t e x'nost eiicientproportions.

. Obviously, the` invention can be applied,

1f necessary, to the gas conduit but, ordi` narily, this will not benecessary, due to the fact that the gas flows directl through the so theinvention is notlimited to systems using gas as a fuelbut, may beapplied with equal advanaga to systems using other forms of fluid Havingdescribed the referred modification of this inventiornw atl claim as newand desire to secure-by Letters Patent is A fuel supply system forfurnaces including a conduit. for delivering fuel thereto, a

conduit for supplying airthereto, a valve f,

for controlling the quantity of air flowing through said air supplyconduit, a second valve located in said air supply conduit between saidlirst mentioned valve and said furnace and means operated entirelyby thepressure in said air supply conduit between said valves for operatingsaid second valve so as to maintain the total resistance from said firstvalve to said furnace constant for 'a iven flow.

n testimony whereof, I have hereunto subscribed my name this 31st day ofAugust,

THOMAS A. PEEBLus.

